The line between consensual sex and sexual assault is not always comfortably clear. Especially when alcohol is involved. Especially in the context of the college hookup culture.

No doubt, sexual assault on campus is a serious problem that authorities have too often ignored. Yet the new insistence that women must not be shamed into silence and that consent must be evident threatens to edge too far the other way, turning young men who may have misread a sexual situation into accused rapists.

Today, no parent of girls should send them off to college without a lecture: Be careful; avoid being pressured into unwanted activity; speak up if something unacceptable occurs. And don’t drink so damn much.

But as a remarkable story in the Yale Daily News demonstrates, every parent of boys should deliver an analogous warning: Protect yourself. Be sure your partner is willing. The consequences of misjudgment can be life-shattering.

The Daily News account, drawn from ordinarily confidential documents provided to reporters Nicole Ng and Vivian Wang by a student who claimed she was raped, offers a chilling look at the complicated new terrain.

The episode occurred in March 2013 between two students who had a typically ambiguous relationship. According to the Daily News, the two “had been involved in a brief yet exclusive romantic relationship the previous fall,” and “had agreed to end all sexual contact just days earlier.”

On the night in question, the female student was playing drinking games with friends in her dorm when the male student texted her. A conversation ensued, with texts that read to an outsider like ambivalent flirtatiousness on the woman’s part, but that she later said were her efforts to head off a sexual encounter.

“Don’t let me try to seduce you though,” she texted at one point, followed by a second: “Because that is a distinct possibility.”

Her next text: “I mean . . . sex is awesome, and I might try to get it from you. But I shouldn’t. I don’t think.”

The male student then texted that his roommates were out and his roommate’s bed was “looking rather comfy.” The woman responded: “None of my roommates are here and I’m too hammered to make it to [your dorm]. Is this a bad idea. . . .”

The male student said he was “on my way.” The woman responded: “Goto [sic] my room I’ll be there soon.”

According to the male student’s account, “little more than ‘Hello’ was said before she grabbed [him], kissed [him] and [they] began to have sex.” “He claimed they each undressed themselves,” the Daily News reported. “They had sex twice that night, he said, and once more in the morning. . . . He said that after their second sexual encounter that night, the complainant said she was sober.”

The woman remembered the incident differently: “She woke up feeling terrible that she had become so inebriated and had sex despite not wanting to. . . . When he initiated sex that morning, the female student said she did not resist because she felt refusal would be too emotionally exhausting.”

Upsetting, but not, the woman initially thought, assault. It was only a few days later that her friends said the man’s actions constituted rape because she was too drunk to consent. “Let’s just start with objective fact: you raped me,” she e-mailed the male student in May. “You are a rapist.”

In the end, an investigative panel decided in favor of the male student. The college dean accepted its findings, although an appeal is possible.

This seems the just outcome, but one that, given the low “preponderance of evidence” standard of proof and Yale’s stringent consent rules, could have gone the other way.

And at what a traumatic cost. To a young woman who sincerely believes she has been raped but seems, at least from afar, to have been pushed by the prevailing culture into viewing a bad choice as a quasi-criminal event. To a young man who lived under the shadow of accusation and expulsion.

This is a cautionary tale about a still-evolving, still-uneasy balance in dealing with sexual assault on campus. The Yale episode demonstrates: Parents of boys should be every bit as nervous as parents of girls about what can happen to the not-quite-adults they send off to college.